1028
S E W BOOKS.
The atomic theory, valency, and the quantitative relations between the weights of substances which enter into a chemical reaction are discussed in a 1-ery satisfactory manner, and are illustrated b y a number of appropriate experiments. The last chapters contain directions for a few of the experiments usually found in the laboratory guides in chemistrJ-. The boob will be helpful to the large number of teachers who, unfortunately, are compelled to teach chemistry to students lvho ha\-e had no training in physics. j~lrr~ .:I s ?\'ORRIS. DIET.U,I,URGT 01; CAST IROS. A complete exposition of tlie processes involved in its treatment, clieniically aiid physically, fi-om t h e hiastfurnace through the foundry to the testing machine. .I iiracticd conipilation of original research. By '1"oMas D. WEST. Fully illustrated. Xinth edition. Cleveland, 0.: The Cleveland Printing and Publishing C o . Price, Sj.00.
That there has been a real need for a comprehensive treatise on this subject and that i t has been met by the book under consideration are evidenced by the issue of nine editions in as many years. It aims to present in 3s plain a way as possible the principles of the smelting of iron ores and the treatment o f cast iron in tlie foundry, together with a discussion of the constitution of the m r i ous grades of iron, the appearance of its fracture as related to the chemical coniposition and the physical effects of impurities normally or occasionally present. Aiconsiderable part of the book is devoted to the mechanical testing of sample bars, and the effects of heat and mechanical treatment are discussed at length. I\lan\of the original investigations of the author and his associates in this field are here recorded. The book can be commended to all those interested in the pmduction or use of cast iron as being both modern and free from unnecessary technicalities. F I < - i r I i JULIAS. EXPEKIXEXTAL RESEARCHESO N THE COSSTITDTIOS O F HYDRAIULIC N O R T A R S . By HENRILECHATELIER. Translated by JOSEPH LATHROP MACK. New Uork : McGraw Publishing Co. Cloth. xznio. 140 pp.
Price,
$2.00.
Mr. Mack has put all persons who do not read French under obligation b y his translation of the thesis of Le Chatelier "On the Constitution of Hydraulic Cements,!' which was presented by him for the Degree of Doctor of Science before the Faculty of Sciences
